Childhood obesity has increased almost three-fold over the past several decades and diagnosis of type 2 diabetes in youth has increased thirty-fold with serious personal health and societal consequences. The purpose of this proposal is to develop and evaluate an instructional computer game called LiFESim in which students will learn scientific evidence for why healthful food and activity choices are important and then to learn ways to navigate and take action on our current food and activity environment to make health-promoting choices. The software for this proposal will be developed from the content and activities of a science education module for 5th-7th graders, Choice, Control &Change (C3) that is part of the Linking Food and the Environment (LiFE) Curriculum Series developed at Teachers College Columbia University and builds on previous modules. C3 uses a unique theoretical approach that fosters students'competence, personal agency, and self-determination related to healthful food and activity choices. The outcome evaluation of the C3 module found students who completed C3, when compared to students who had the standard science curriculum, reported improved eating and physical activity behaviors. The primary aim of the LifeSim evaluation is to determine if the LiFESim computer instructional game can have positive student outcomes, as does the C3 curriculum. The same aged students and the same outcome variables as for C3 for will be measured for the LifeSim evaluation. If LiFESim is found to be effective it will provide an alternative way for 5th-7th students to receive the C3 content that may be more flexible for teachers and engaging for students. The specific aims of this phase II proposal are to revise the LiFESim game developed in phase 1, adapt the C3 evaluation instruments and methods to make them appropriate for evaluating the LiFESim game, and formatively and summatively evaluate the LiFESim game in 5th-7th grade classrooms in New York City Schools. We initially plan to commercialize this software by packaging it with the LiFE curriculum. PUBLIC HEALTH RELEVANCE: The principal benefit that we hope to achieve in LifeSim is to influence changes in eating and physical activity behaviors of the students using LifeSim to aid in the prevention of childhood obesity. We are looking at influencing the following specific behaviors and their influences:1) eat more fruit and vegetables;2) drink fewer sweetened beverages and more water;3) eat less frequently at fast food establishments;4) eat fewer prepackaged snacks;5) increase moderate and vigorous physical activity;and 6) decrease recreational screen-time. Society will benefit from this by having healthier youth and potential reduction in healthcare costs.